This is the most frustrating part of overal work. Render and capture.  In 3D saying its like ray tracing.   Print screen every layer of parts, cut, paste, re align and labelling.   Each view port print screen will take at least 5 layer of screenshots depending how much layered parts placed on the models.   As for VEXUVIUS there are 5 layers:  Main body, dark panel, glass, grills and linear parts.  All the 5 layers use different UV mapping style after templating is done due to the fact all this to ensure quality non-jagged UV mapping on the models.